Reduce memory usage of meshlink_join().

Reduce the size of the buffers, and allocate the join state on the heap.

diff --git a/src/meshlink.c b/src/meshlink.c
index ec8024e58031c829584d4cf117960fa5cad8a58a..aadbaf337cca4798500544ed19c67aef67fa1bcd 100644 (file)
--- a/src/meshlink.c
+++ b/src/meshlink.c
@@ -45,6 +45,8 @@ meshlink_log_level_t global_log_level;
 
 typedef bool (*search_node_by_condition_t)(const node_t *, const void *);
 
+#define BUFSIZE 128
+
 static int rstrip(char *value) {
        int len = strlen(value);
 
@@ -152,7 +154,7 @@ static bool write_main_config_files(meshlink_handle_t *mesh) {
                return true;
        }
 
-       uint8_t buf[4096];
+       uint8_t buf[BUFSIZE];
 
        /* Write the main config file */
        packmsg_output_t out = {buf, sizeof buf};
@@ -191,8 +193,8 @@ typedef struct {
        char *data;
        size_t thedatalen;
        size_t blen;
-       char line[4096];
-       char buffer[4096];
+       char line[BUFSIZE];
+       char buffer[BUFSIZE];
 } join_state_t;
 
 static bool finalize_join(join_state_t *state, const void *buf, uint16_t len) {
@@ -417,7 +419,7 @@ static bool recvline(join_state_t *state) {
 }
 
 static bool sendline(int fd, const char *format, ...) {
-       char buffer[4096];
+       char buffer[BUFSIZE];
        char *p = buffer;
        int blen = 0;
        va_list ap;
@@ -1729,16 +1731,15 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) {
                return false;
        }
 
-       join_state_t state = {
-               .mesh = mesh,
-               .sock = -1,
-       };
+       join_state_t *state = xzalloc(sizeof * state);
+       state->mesh = mesh;
+       state->sock = -1;
 
        ecdsa_t *key = NULL;
        ecdsa_t *hiskey = NULL;
 
        //TODO: think of a better name for this variable, or of a different way to tokenize the invitation URL.
-       char copy[strlen(invitation) + 1];
+       char *copy = xstrdup(invitation);
 
        if(pthread_mutex_lock(&mesh->mutex) != 0) {
                abort();
@@ -1758,8 +1759,6 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) {
                goto exit;
        }
 
-       strcpy(copy, invitation);
-
        // Split the invitation URL into a list of hostname/port tuples, a key hash and a cookie.
 
        char *slash = strchr(copy, '/');
@@ -1777,16 +1776,19 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) {
        char *address = copy;
        char *port = NULL;
 
-       if(!b64decode(slash, state.hash, 18) || !b64decode(slash + 24, state.cookie, 18)) {
+       if(!b64decode(slash, state->hash, 18) || !b64decode(slash + 24, state->cookie, 18)) {
                goto invalid;
        }
 
+       logger(mesh, MESHLINK_DEBUG, "Done");
+
        if(mesh->inviter_commits_first) {
-               memcpy(state.cookie + 18, ecdsa_get_public_key(mesh->private_key), 32);
+               memcpy(state->cookie + 18, ecdsa_get_public_key(mesh->private_key), 32);
        }
 
        // Generate a throw-away key for the invitation.
        key = ecdsa_generate();
+       logger(mesh, MESHLINK_DEBUG, "Done");
 
        if(!key) {
                meshlink_errno = MESHLINK_EINTERNAL;
@@ -1834,9 +1836,9 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) {
 
                if(ai) {
                        for(struct addrinfo *aip = ai; aip; aip = aip->ai_next) {
-                               state.sock = socket_in_netns(aip->ai_family, SOCK_STREAM, IPPROTO_TCP, mesh->netns);
+                               state->sock = socket_in_netns(aip->ai_family, SOCK_STREAM, IPPROTO_TCP, mesh->netns);
 
-                               if(state.sock == -1) {
+                               if(state->sock == -1) {
                                        logger(mesh, MESHLINK_DEBUG, "Could not open socket: %s\n", strerror(errno));
                                        meshlink_errno = MESHLINK_ENETWORK;
                                        continue;
@@ -1844,16 +1846,16 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) {
 
 #ifdef SO_NOSIGPIPE
                                int nosigpipe = 1;
-                               setsockopt(state.sock, SOL_SOCKET, SO_NOSIGPIPE, &nosigpipe, sizeof(nosigpipe));
+                               setsockopt(state->sock, SOL_SOCKET, SO_NOSIGPIPE, &nosigpipe, sizeof(nosigpipe));
 #endif
 
-                               set_timeout(state.sock, 5000);
+                               set_timeout(state->sock, 5000);
 
-                               if(connect(state.sock, aip->ai_addr, aip->ai_addrlen)) {
+                               if(connect(state->sock, aip->ai_addr, aip->ai_addrlen)) {
                                        logger(mesh, MESHLINK_DEBUG, "Could not connect to %s port %s: %s\n", address, port, strerror(errno));
                                        meshlink_errno = MESHLINK_ENETWORK;
-                                       closesocket(state.sock);
-                                       state.sock = -1;
+                                       closesocket(state->sock);
+                                       state->sock = -1;
                                        continue;
                                }
 
@@ -1865,14 +1867,14 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) {
                        meshlink_errno = MESHLINK_ERESOLV;
                }
 
-               if(state.sock != -1 || !comma) {
+               if(state->sock != -1 || !comma) {
                        break;
                }
 
                address = comma;
        }
 
-       if(state.sock == -1) {
+       if(state->sock == -1) {
                goto exit;
        }
 
@@ -1880,9 +1882,9 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) {
 
        // Tell him we have an invitation, and give him our throw-away key.
 
-       state.blen = 0;
+       state->blen = 0;
 
-       if(!sendline(state.sock, "0 ?%s %d.%d %s", b64key, PROT_MAJOR, PROT_MINOR, mesh->appname)) {
+       if(!sendline(state->sock, "0 ?%s %d.%d %s", b64key, PROT_MAJOR, PROT_MINOR, mesh->appname)) {
                logger(mesh, MESHLINK_ERROR, "Error sending request to %s port %s: %s\n", address, port, strerror(errno));
                meshlink_errno = MESHLINK_ENETWORK;
                goto exit;
@@ -1890,27 +1892,27 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) {
 
        free(b64key);
 
-       char hisname[4096] = "";
+       char hisname[BUFSIZE] = "";
        int code, hismajor, hisminor = 0;
 
-       if(!recvline(&state) || sscanf(state.line, "%d %s %d.%d", &code, hisname, &hismajor, &hisminor) < 3 || code != 0 || hismajor != PROT_MAJOR || !check_id(hisname) || !recvline(&state) || !rstrip(state.line) || sscanf(state.line, "%d ", &code) != 1 || code != ACK || strlen(state.line) < 3) {
+       if(!recvline(state) || sscanf(state->line, "%d %s %d.%d", &code, hisname, &hismajor, &hisminor) < 3 || code != 0 || hismajor != PROT_MAJOR || !check_id(hisname) || !recvline(state) || !rstrip(state->line) || sscanf(state->line, "%d ", &code) != 1 || code != ACK || strlen(state->line) < 3) {
                logger(mesh, MESHLINK_ERROR, "Cannot read greeting from peer\n");
                meshlink_errno = MESHLINK_ENETWORK;
                goto exit;
        }
 
        // Check if the hash of the key he gave us matches the hash in the URL.
-       char *fingerprint = state.line + 2;
+       char *fingerprint = state->line + 2;
        char hishash[64];
 
        if(sha512(fingerprint, strlen(fingerprint), hishash)) {
-               logger(mesh, MESHLINK_ERROR, "Could not create hash\n%s\n", state.line + 2);
+               logger(mesh, MESHLINK_ERROR, "Could not create hash\n%s\n", state->line + 2);
                meshlink_errno = MESHLINK_EINTERNAL;
                goto exit;
        }
 
-       if(memcmp(hishash, state.hash, 18)) {
-               logger(mesh, MESHLINK_ERROR, "Peer has an invalid key!\n%s\n", state.line + 2);
+       if(memcmp(hishash, state->hash, 18)) {
+               logger(mesh, MESHLINK_ERROR, "Peer has an invalid key!\n%s\n", state->line + 2);
                meshlink_errno = MESHLINK_EPEER;
                goto exit;
        }
@@ -1923,47 +1925,55 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) {
        }
 
        // Start an SPTPS session
-       if(!sptps_start(&state.sptps, &state, true, false, key, hiskey, meshlink_invitation_label, sizeof(meshlink_invitation_label), invitation_send, invitation_receive)) {
+       if(!sptps_start(&state->sptps, state, true, false, key, hiskey, meshlink_invitation_label, sizeof(meshlink_invitation_label), invitation_send, invitation_receive)) {
                meshlink_errno = MESHLINK_EINTERNAL;
                goto exit;
        }
 
        // Feed rest of input buffer to SPTPS
-       if(!sptps_receive_data(&state.sptps, state.buffer, state.blen)) {
+       if(!sptps_receive_data(&state->sptps, state->buffer, state->blen)) {
                meshlink_errno = MESHLINK_EPEER;
                goto exit;
        }
 
        ssize_t len;
-       logger(mesh, MESHLINK_DEBUG, "Starting invitation recv loop: %d %zu\n", state.sock, sizeof(state.line));
+       logger(mesh, MESHLINK_DEBUG, "Starting invitation recv loop: %d %zu\n", state->sock, sizeof(state->line));
 
-       while((len = recv(state.sock, state.line, sizeof(state.line), 0))) {
+       while((len = recv(state->sock, state->line, sizeof(state->line), 0))) {
                if(len < 0) {
                        if(errno == EINTR) {
                                continue;
                        }
 
+                       if(errno == ENOTCONN) {
+                               break;
+                       }
+
                        logger(mesh, MESHLINK_ERROR, "Error reading data from %s port %s: %s\n", address, port, strerror(errno));
                        meshlink_errno = MESHLINK_ENETWORK;
                        goto exit;
                }
 
-               if(!sptps_receive_data(&state.sptps, state.line, len)) {
+               if(!sptps_receive_data(&state->sptps, state->line, len)) {
                        meshlink_errno = MESHLINK_EPEER;
                        goto exit;
                }
+
+               if(state->success) {
+                       break;
+               }
        }
 
-       if(!state.success) {
+       if(!state->success) {
                logger(mesh, MESHLINK_ERROR, "Connection closed by peer, invitation cancelled.\n");
                meshlink_errno = MESHLINK_EPEER;
                goto exit;
        }
 
-       sptps_stop(&state.sptps);
+       sptps_stop(&state->sptps);
        ecdsa_free(hiskey);
        ecdsa_free(key);
-       closesocket(state.sock);
+       closesocket(state->sock);
 
        pthread_mutex_unlock(&mesh->mutex);
        return true;
@@ -1972,15 +1982,16 @@ invalid:
        logger(mesh, MESHLINK_ERROR, "Invalid invitation URL\n");
        meshlink_errno = MESHLINK_EINVAL;
 exit:
-       sptps_stop(&state.sptps);
+       sptps_stop(&state->sptps);
        ecdsa_free(hiskey);
        ecdsa_free(key);
 
-       if(state.sock != -1) {
-               closesocket(state.sock);
+       if(state->sock != -1) {
+               closesocket(state->sock);
        }
 
        pthread_mutex_unlock(&mesh->mutex);
+       free(copy);
        return false;
 }
 
@@ -1992,7 +2003,7 @@ char *meshlink_export(meshlink_handle_t *mesh) {
 
        // Create a config file on the fly.
 
-       uint8_t buf[4096];
+       uint8_t buf[BUFSIZE];
        packmsg_output_t out = {buf, sizeof(buf)};
        packmsg_add_uint32(&out, MESHLINK_CONFIG_VERSION);
        packmsg_add_str(&out, mesh->name);